TSCR-MAC: Time-slotted channel reservation based cognitive MAC

A novel multichannel MAC protocol called time slotted channel reservation based MAC protocol (TSCR-MAC) for cognitive radio networks is introduced, specified, illustrated and simulated. TSCR-MAC demands only one half-duplex CR radio and employs common control channel for information exchange. In TSCR-MAC a time slot is assigned a separate frequency channel. It allows a pair of communicating nodes to reserve a channel in the allocated slot via reservation operation and handshake mechanism. Fresh node pairs contend the unoccupied channel by a p-persistent fashion in the meantime and the probability value is dynamically adjusted according to the historical information and current available channel. In this paper, TSCR-MAC protocol and frame structure are fully described. The simulated results show that TSCR-MAC can not only achieve much higher average throughput but also provide better spectrum utilization and delay performance, compared with multichannel ALOHA and traditional reservation schedule.